Almost every kind of pressure sensitive adhesive (PSA) article in use today is cut in some way, e.g., during manufacturing as the article is being made, or when the article is being adapted by a customer for some specific use. Applications in which PSA articles may be used continue to grow, as does the need for cutting the articles into more custom and complicated shapes.
PSA materials and articles can be difficult to cut. Past approaches have relied on balancing the properties of a given PSA such that it is soft enough to adhere in a desired function/application, yet is able to resist any flow that would lead to undesired effects when die cut. Some of the undesired effects of such flow include sticky residue left on both the cutting blade and the cut edges of the PSA article. Also, if the PSA is viscoelastic, it can dampen out some of the energy used to cut the PSA, and energy can be lost into the PSA itself. For PSA articles having a backing, an approach for improving die cutting performance of PSA materials is to increase the stiffness of the backing. Other approaches impose limitations on the PSAs (chemically and rheologically) to satisfy the needs of the die cutting process.
Dispensing labels includes the steps of separation of the labels from a liner, and the application of each label to a substrate surface. Typically, the label can be separated from the liner by bending the liner back over a peel-plate such that the peel-plate causes separation of the label from the liner. If the label is stiff enough, it will continue on a straight path toward the desired substrate surface overcoming the release force between the label adhesive and the release liner. The stiffness needed for dispensability can limit the choice of materials that can be used as well as the overall design of the label.